Cardiac catheterization and angioplasty are common medical procedures. The coronary arteries are vessels which supply the heart muscle with blood and are located on the outside surface of the heart. In order to visually examine the coronary arteries, a contrast agent has to be injected into the vessels before x-ray pictures can be taken of them. This is accomplished through a procedure called cardiac catheterization. This contrast agent is delivered through a catheter, which is a small hollow tube. This catheter is advanced to the heart under x-ray guidance, usually being inserted at the level of the groin into the femoral artery. This is accomplished through a needle which is first advanced into the femoral artery and subsequently the catheter is passed through the needle into the blood vessel or femoral artery. The femoral artery in turn is a tributary of the great vessel originating in the heart and therefore the catheter can be passed in a retrograde fashion under x-ray guidance very easily back to the origin of the coronary arteries.
Once the catheter is positioned at the origin of the coronary arteries, a dye syringe is placed on the end of the catheter remaining outside the patient and injections are performed with simultaneous x-ray pictures being taken.
An angioplasty procedure is similar in technique but more invasive, by the fact that a smaller catheter with a deflated balloon on its tip is advanced through the catheter which is positioned at the origin of the coronary artery and advanced down into the coronary artery to the site of where the vessel is narrowed. The balloon dilatation catheter is not advanced down the coronary artery by itself; however, first, a very small guide wire is advanced down the coronary artery, across the narrowed segment and then advanced further down into the coronary artery, beyond the narrowed segment. The balloon dilatation catheter is then advanced over the guide wire to the site of the narrowing. The guide wire allows the balloon dilatation catheter to track over it, thereby facilitating advancement of the balloon dilatation catheter down the vessel and thus preventing damage to the vessel wall. Once the balloon is positioned at the site of the narrowing in the vessel, the balloon is inflated by means of a hand held balloon inflation device. The balloon is inflated for generally 30 to 90 seconds and then deflated and withdrawn. This compresses the fatty-like material which is responsible for narrowing the coronary artery and opens the vessel, allowing for proper blood flow to the heart muscle.
At times it is difficult to advance the balloon dilatation catheter to the site of the narrowing, as these vessels are not always straight and often times bends in the vessel have to be negotiated before reaching the point of narrowing. Frequently, the balloon dilatation catheter cannot be easily advanced and the guiding catheter which is housing the balloon dilatation catheter and the guide wire comes loose from its position at the origin of the coronary artery and does not provide enough structural support or backup to allow advancement of the balloon dilatation catheter to the narrowed site.
Improvements in this field have been made such as for example, the angioplasty method and means for performing angioplasty seen in U.S. Pat. No. 5,484,412. Specifically, in this patent a method and means is provided using a plurality of different catheters that are all interconnected using a plurality of balloons to provide more accurate handling and control to improve angioplasty procedures. Despite this improved means and method additional improvements are desired. Specifically, a need exists for the use of non inflatable equipment that accomplishes similar results.
Thus, the principal object of the present invention is to provide an improved method and means for performing an angioplasty that provides structural support to the guiding catheter.
Another object of the invention is to provide catheter designs having the capability of proximal embolic protection.
These and other objects, features, or advantages of the present will become apparent from the specification and claims.